Biologically active synthetic fragments of bradykinin.

Bradykinin, Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg, is released from bradykininogen by the action of kallikreins and brings about smooth muscle stimulation, vasodilation, increase in capillary permeability, ac cumulation and migration of leucocytes and pain production. It is well known that so-called kininase, for example catheptic carboxypeptidase B and carboxypeptidase N, destroy bradykinin by cleaving the peptide bond of the nonapeptide, producing pharmacologically inert peptides (1, 2). However, there is a posibility